Glass run channel, glass run channel assembly and manufacturing method of glass run channel

ABSTRACT

A glass run channel having an elongated shape, which is mounted on a window frame of a vehicle door, guides moving up and down of a windowpane and is made of a polymer material, the glass run channel including a run channel main body that forms the main part of the glass run channel, the run channel main body including, a base bottom portion, an interior side wall portion, an exterior side wall portion, an interior seal lip and an exterior seal lip, wherein the run channel main body has a foamed part made of a foamable polymer material that includes a thermoplastic elastomer material and thermal expansion capsules, and has foaming cells which are formed by expansion of the thermal expansion capsules, and wherein a water absorption rate of the foamed part of the run channel main body is adjusted to 5% or less.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Patent Application No.2010-084996 filed on Apr. 1, 2010, and from Japanese Patent ApplicationNo. 2010-293100 filed on Dec. 28, 2010, the entire contents of which areincorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a glass run channel, a grass runchannel assembly and a manufacturing method of a glass run channel.

BACKGROUND

For example, a glass run channel, which is mounted on a run mountingportion of a window frame that is provided along a window opening edgeof a front door or a rear door of a vehicle and which guides moving upand down of a windowpane, is made of a rubber material or a polymermaterial (a thermoplastic elastomer material).

Further, a glass run channel, which is constituted of a foaming bodythat has countless foaming cells so as to achieve a reduction in weightof the glass run channel, is known.

Related-art discloses a glass run channel, in which microcapsules(thermal expansion capsules) are mixed with the rubber material, foamedand expanded.

Further, related-art discloses a glass run channel in which a chemicalfoaming agent is mixed to the polymer material, foamed and expanded.

In the related-art glass run channel made of foaming rubber, it isdifficult to reduce the specific gravity and reduce the weight comparedto the related-art glass run channel made of foamable polymer (made ofthermoplastic elastomer).

Further, in the glass run channel made of foamable polymer, the chemicalfoaming agent is mixed with the polymer material, whereby expansionoccurs. Thus, the countless foaming cells easily become opened cellsthat communicate with each other, and fluid, such as water, is easilyabsorbed.

Accordingly, after the polymer material that is mixed with the chemicalfoaming agent is extruded from an outlet of a mold of the extrusionmolding machine and the molding body having a shape corresponding to thecross-sectional shape of the glass run channel is formed, when themolding body is, for example, cooled and solidified by coolant water inmanufacturing the glass run channel, the glass run channel absorbs thecoolant water.

Thus, after the glass run channel is cooled and solidified, a dryingprocess is required so as to vaporize fluid that is absorbed within theglass run channel.

The glass run channel absorbs the fluid even in a use state in which theglass run channel is mounted on the run mounting portion of the windowframe of the front door or the rear door. Thus, when outdoor temperatureis a low temperature, fluid within the glass run channel is frozen andthe glass run channel is excessively hardened so that there is apossibility that abnormal noise will be generated when the windowpane ismoved up and down.

SUMMARY

Accordingly, an object of the invention is to provide a glass runchannel which can be lightweight and suppress the absorption of fluid, aglass run channel assembly using the glass run channel, and amanufacturing method of the glass run channel.

According to an aspect of the invention, there is provided a glass runchannel having an elongated shape, which is mounted on a run mountingportion of a window frame of a vehicle door, guides moving up and downof a windowpane and is made of a polymer material, the glass run channelcomprising: a run channel main body that forms the main part of theglass run channel, the run channel main body including, a base bottomportion which is provided at a position facing an end surface of thewindowpane; an interior side wall portion which extends from a width endof the base bottom portion, an exterior side wall portion which extendsfrom another width end of the base bottom portion, an interior seal lip,which projects toward the base bottom portion from an opening side endof the interior side wall portion and elastically contacts a firstsurface of the windowpane, and an exterior seal lip, which projectstoward the base bottom portion from an opening side end of the exteriorside wall portion and elastically contacts a second surface of thewindowpane, wherein the run channel main body has a foamed part made ofa foamable polymer material that includes a thermoplastic elastomermaterial and thermal expansion capsules, and has foaming cells which areformed by expansion of the thermal expansion capsules, and wherein awater absorption rate of the foamed part of the run channel main body isadjusted to 5% or less.

According to another aspect of the present invention, there is provideda glass run channel assembly including at least two above-describedglass run channels, wherein the at least two glass run channels arejoined and constituted in an integrally continuous shape to each otherby a connecting body.

According to another aspect of the invention, there is provided a methodof manufacturing the above-described glass run channel, the methodcomprising: inputting a thermoplastic elastomer material and amasterbatch material into a extrusion molding machine in an adjustedweight ratio, wherein the masterbatch material is formed by mixing thethermal expansion capsules with the thermoplastic resin material, thethermoplastic resin material being the same material as thethermoplastic elastomer material or being miscible with thethermoplastic elastomer material, providing a foamable polymer materialby heating and pressurizing each material while mixing in the extrusionmolding machine; supplying the foamable polymer material to a moldextruding the foamable polymer material from an outlet of the mold ofthe extrusion molding machine after supplying the foamable polymermaterial to the mold; forming a molding body of a shape corresponding toa cross-sectional shape of the glass run channel by expanding andfoaming the thermal expansion capsules immediately after the extrusion;and cooling and solidifying the molding body after the foaming.

According to another aspect of the present invention, there is provideda glass run channel having an elongated shape, which is mounted on a runmounting portion of a window frame of a vehicle door, guides moving upand down of a windowpane and is made of a polymer material, the glassrun channel comprising: a run channel main body that forms the main partof the glass run channel, the run channel main body including, a basebottom portion which is provided at a position facing an end surface ofthe windowpane; an interior side wall portion which extends from a widthend of the base bottom portion, an exterior side wall portion whichextends from another width end of the base bottom portion, an interiorseal lip, which projects toward the base bottom portion from an openingside end of the interior side wall portion and elastically contacts afirst surface of the windowpane, and an exterior seal lip, whichprojects toward the base bottom portion from an opening side end of theexterior side wall portion and elastically contacts a second surface ofthe windowpane, wherein the base bottom portion, the interior side wallportion, the exterior side wall portion and the interior seal lipportion are made of a foamable polymer material that includes athermoplastic elastomer material and thermal expansion capsules, and hasfoaming cells which are formed by expansion of the thermal expansioncapsules, and wherein each water absorption rate of the base bottomportion, the interior side wall portion, the exterior side wall portionand the interior seal lip portion is adjusted to 5% or less.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view schematically illustrating a state in which glassrun channel assemblies, which use glass run channels according to afirst exemplary embodiment of the invention, are provided at a windowframe of a front door and a window frame of a rear door respectively;

FIG. 2 is a side view illustrating the glass run channel assembly;

FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1,illustrating the glass run channel;

FIG. 4 is a cross-sectional view illustrating the glass run channelaccording to another exemplary embodiment of the invention; and

FIG. 5 is an explanation view illustrating a relationship between awater absorption rate and a specific gravity of a foamable polymer whichforms a foaming part of a run channel main body.

DETAILED DESCRIPTION

The first exemplary embodiment embodying a mode for carrying out theinvention will be described.

The first exemplary embodiment of the invention will be described withreference to FIGS. 1 to 3.

As shown in FIG. 1, a window frame 20 is integrally formed at a doorpanel 12 that forms a front door 10 as a vehicle door.

A run mounting portion 25 is formed at the window frame 20. The runmounting portion 25 is formed by an outer panel 13 and an inner panel 14which constitute the door panel 12 in a step shape which an opening sideis narrow and an inner side is wide (see FIG. 3).

As shown in FIGS. 1 and 2, a front side glass run channel assembly 30 ismounted on the window frame 20 of the front door 10 as the vehicle doorso as to guide a moving up and down operation of a windowpane 15. Thefront side glass run channel assembly 30 has an elongated shape and ismade of polymer material (thermoplastic elastomer material). The glassrun channel assembly 30 has first to fourth glass run channels 31, 32,33 and 34 which are formed in elongated shapes by extrusion molding, andfirst to third connecting bodies 41, 42 and 43 which are formed byinjection molding.

The first glass run channel 31 is mounted along an upper side portionand a front oblique side portion of the front door 10.

An upper end of the second glass run channel 32 is connected to a rearend of the first glass run channel 31 by the first connecting body (thecorner connecting body) 41. The second glass run channel 32 is mountedalong a rear vertical side portion of the front door 10.

An upper end of the third glass run channel 33 is connected to a frontend of the first glass run channel 31 by the second connecting body (acorner connecting body) 42. The third glass run channel 33 is mountedalong the front vertical frame portion which extends from a rear edge ofa front quarter window of the front door 10 to the inside of the door.

A lower end of the second glass run channel 32 is arranged within thedoor and an upper end of the fourth glass run channel 34 is connected tothe lower end of the second glass run channel 32 by the third connectingbody 43. The fourth glass run channel 34 is mounted along the rearvertical frame portion within the door.

Among the first to the fourth glass run channels 31 to 34 whichconstitute the front side glass run channel assembly 30, the first glassrun channel 31 is constituted by an extrusion molding product having across-sectional shape as shown in FIG. 3.

A run channel main body 50 that forms a main part of the first glass runchannel 31 includes a base bottom portion 51 that is provided at aposition that faces an end surface of the windowpane 15, an exteriorside wall portion 52 which extends from a width end of the base bottomportion and an interior side wall portion 53 which extends from anotherwidth end of the base bottom portion 51. The exterior side wall portion52 and the interior side wall portion 53 constitute a sliding recess inwhich a peripheral portion of the windowpane 15 can be inserted.Further, the run channel main body 50 may include an exterior seal lip62, an interior seal lip 65, or both. The exterior seal lip 62 projectstoward the base bottom portion 51 from a top connecting portion 56 whichis an opening side end of the exterior side wall portion 52. Theinterior seal lip 65 projects toward the base bottom portion 51 from atop connecting portion 57 which is an opening side end of the interiorside wall portion 53. The exterior seal lip 62 and the interior seal lip65 is configured to elastically contact each surfaces of the windowpane15 respectively.

Further, the run channel main body 50 may include an exterior decorationportion 67, an interior decoration portion 68, or both. The exteriordecoration portion 67 projects from the top connecting portion 56 andthe interior decoration portion 68 projects from the top connectingportion 57. The exterior decoration portion 67 projects toward anopposite side of the exterior seal lip 62 and is formed in a foldedshape along the exterior side wall portion 52. The interior decorationportion 68 projects toward an opposite side of the interior seal lip 65,and is formed in a folded shape along the interior side wall portion 53.

The run channel main body 50 may include an exterior holding lip 60having a lip shape, an interior holding lip 61 having a lip shape, orboth. The exterior holding lip 60 is provided outside of an end portionof the exterior side wall portion 52 at the base bottom portion 51 side.The interior holding lip 61 is provided outside of an end portion of theinterior side wall portion 53 at the base bottom portion 51 side. Theexterior holding lip 60 and the interior holding lip 61 are inclined andprojected from the exterior side wall portion 52 and the interior sidewall portion 53 respectively. Further, the exterior holding lip 60 iselastically engaged and retained to an exterior step portion 13 a of thewindow frame 20. The interior holding lip 61 is elastically engaged andretained to an interior step portion 14 a of the window frame 20.

In the first exemplary embodiment, an exterior low friction layer 63 isformed at a surface of the exterior seal lip 62, which contacts thewindowpane 15, and an interior low friction layer 66 is formed at asurface of the interior seal lip 65, which contacts the windowpane 15.The low friction layers 63 and 66 are formed by a co-extrusion(two-color molding) with the extrusion molding of the run channel mainbody 50, by using a material, which is the same kind of material as amaterial of the run channel main body 50 or a material which is misciblewith the material of the run channel main body 50, and which is a lowfriction material (the thermoplastic elastomer material or thethermoplastic resin material), that is, a coefficient of kineticfriction of the material is smaller than that of the material of the runchannel main body 50.

Further, low friction layers 52 a, 53 a and 51 a are made of a lowfriction material that has a coefficient of kinetic friction smallerthan that of the material of the run channel main body 50. The lowfriction layers 52 a, 53 a and 51 a are respectively formed on surfacesof the both side wall portions 52 and 53 that face each other and abottom surface of the base bottom portion 51. The low friction layers 52a, 53 a and 51 a are formed by co-extrusion (two-color molding)simultaneously with the extrusion molding of the run channel main body50.

The run channel main body 50 has a foamed part that is made of afoamable polymer material that includes a thermoplastic elastomermaterial and thermal expansion capsules, and has countless foaming cellswhich are formed by the expansion of the thermal expansion capsules. Thewater absorption rate of the foamed part of the run channel main body 50is adjusted to be 5% or less.

It is preferred that the water absorption rate of the foamed part of therun channel main body 50 is 1% or less.

Additionally, it is preferred that a specific gravity of the foamed partof the run channel main body 50 is 0.50 to 0.75. It is further preferredthat the specific gravity of the foamed part of the run channel mainbody 50 is 0.65.

The water absorption rate of the foamed part of the run channel mainbody 50 is measured by a method described hereinafter.

(1) First, a glass run channel (the first to the fourth glass runchannels 31 to 34) in which the run channel main body 50 as a main bodyis cut to a length of 50 mm, so as to form a measuring piece.

(2) The weight of the measuring piece (W0) is measured.

(3) The measuring piece is deposited in a container that is filled withwater. At this time, the measuring piece is dipped into the water sothat a position of an upper end of the measuring piece is at a depth of50 mm or more from a water surface of the container and a position ofthe lower end of the measuring piece is separated by 30 mm to 50 mm fromthe bottom surface of the container.

(4) The entire container in which the measuring piece is dipped isdepressurized to 17 kPa (127.5 mmHg) for 5 minutes and then left at anatmospheric pressure for 3 minutes.

(5) The measuring piece is taken out from the container, water dropletsthat are attached the surface of the measuring piece are removed andthen the weight (W1) of the measuring piece after dipping is measured.

(6) After that, a weight change rate (Δm) of the measuring piece iscalculated based on the formula of Δm=[(W1−W0)/W0]×100.

(7) The above described processes (1) to (6) is performed with respectto a plurality (three or more) of measuring pieces and the average ofthe value of Δms is calculated. The average of the value of Δms is thewater absorption rate of the foamed part of the run channel main body50.

As described previously, in the foamable polymer material that forms thefoamed part of the run channel main body 50, 0.5 to 2.0 parts by weightof the thermal expansion capsules are mixed with 100 parts by weight ofthe thermoplastic elastomer material so that the water absorption rateof the foamed part of the run channel main body 50 is 5% or less and thespecific gravity of the foamed part of the run channel main body 50 is0.50 to 0.75.

It is further preferred that, in the foamable polymer material thatforms the foamed part of the run channel main body 50, 1.0 part byweight of the thermal expansion capsules are mixed with respect to 100parts by weight of the thermoplastic elastomer material so that thewater absorption rate of the foamed part of the run channel main body 50is 1% or less and the specific gravity of the foamed part of the runchannel main body 50 is 0.65.

It is preferred that the foamed part of the run channel main body 50 isformed such that the inner foaming cells inside thereof are closed cellsthat do not communicate with external air. It is further preferred thatthe foaming cells are closed cells that do not communicate with eachother inside the run channel main body 50.

A run channel main body that forms the main part of the second, thethird and the fourth glass run channels 32, 33 and 34, among the firstto fourth glass run channels 31 to 34 which constitute the front sideglass run channel assembly 30, is constituted in the same manner as therun channel main body 50 that constitutes the main part of the firstglass run channel 31 except that the cross-sectional shape thereof isdifferent.

That is, the foamed part of the run channel main body that forms themain part of the second, the third and the fourth glass run channels 32,33 and 34 are also made of the foamable polymer material that includesthe thermoplastic elastomer material and the thermal expansion capsule,and have countless foaming cells which are formed by the expansion ofthe thermal expansion capsules.

Among the first to fourth glass run channels 31 to 34, two or more glassrun channels may have the same cross-sectional shape. For example, thesecond glass run channel 32 and the third glass run channel 33 may havethe same cross-sectional shape.

The glass run channel according to the first exemplary embodiment of theinvention is configured as described above.

Accordingly, since the foamed part of the run channel main body 50 thatforms the main part of the first to the fourth glass run channels 31 to34 that constitute the front side glass run channel assembly 30 is madeof the foamable polymer material that includes the thermoplasticelastomer material and the thermal expansion capsule, the run channelmain body 50 can be reduced in weight compared to the glass run channelmade of rubber.

Further, the water absorption rate of the foamed part of the run channelmain body 50 is adjusted to 5% or less so that water is not easilyabsorbed within the foaming cells.

As a result, in the manufacturing process of the glass run channel,since only a little amount of water is absorbed within the glass runchannel (the first to the fourth glass run channels 31 to 34 whichconstitute the front side glass run channel assembly 30), the littleamount of water is not required to be vaporized and dried after theglass run channel is cooled and solidified by the cooling water so thatthe drying process time can be shortened or the drying process can becancelled.

Further, the run channel main body 50 is prevented from absorbing watereven in a state in which the front side glass run channel assembly 30 ismounted and used at the run mounting portion of the window frame 20 ofthe front door 10. Thus, even when outdoor temperature is a lowtemperature, the run channel main body 50 is not excessively hardeneddue to the water within the run channel main body 50 being frozen, andthe problem of the generation of abnormal noise when the windowpane ismoved up and down is prevented.

Further, by adjusting the water absorption rate of the foamed part ofthe run channel main body 50 to 1% or less, the water is even lesseasily absorbed within the foam cells.

It is preferred that the specific gravity of the foamed part of the runchannel main body 50 is 0.50 to 0.75.

That is, if the specific gravity of the foamed part of the run channelmain body 50 is less than 0.50, the water absorption rate may increase.

Further, if the specific gravity of the foamed part of the run channelmain body 50 is more than 0.75, the weight reduction effect willdecrease.

It is further preferred that the foamed part of the specific gravity ofthe run channel main body 50 is 0.65.

In the foamable polymer material that forms the foamed part of the runchannel main body 50, 0.5 to 2.0 parts by weight of the thermalexpansion capsules are mixed with 100 parts by weight of thethermoplastic elastomer material. Thus, the weight reduction issatisfactorily performed and the water absorption rate can be maintainedto be 5% or less.

In other words, if the thermal expansion capsules are less than 0.5parts by weight, the weight reduction effect will decrease.

If the thermal expansion capsules are more than 2.0 parts by weight, thecapsules may become an excessively foamed state so that rigidity,tensile strength and the like decrease, or the foaming cells may becomecontinuous to each other so that it is difficult to maintain the waterabsorption rate at 5% or less.

Further, in the foamable polymer material that forms the foamed part ofthe run channel main body 50, if 1.0 part by weight of the thermalexpansion capsules is mixed with respect to 100 parts by weight of thethermoplastic elastomer material, the weight reduction effect and thesuppression effect on the water absorption rate further increases.

Meanwhile, the specific gravity or the water absorption rate of thefoamed part of the run channel main body 50 can be adjusted by otherconditions than the mixing amount of the thermal expansion capsules.Specifically, a foaming state of the thermal expansion capsules can beadjusted by temperature or the rotation speed of a screw of theextrusion molding machine when the glass run channel is extrusionmolded.

The foamed part of the run channel main body 50 is formed such that thefoaming cells inside thereof are closed cells that do not communicatewith the external air. Accordingly, the water is satisfactorilyprevented from being absorbed inside the run channel main body 50 fromthe surface of the run channel main body and the suppression effect onthe water absorption rate increases.

The foamed part of the run channel main body 50 is formed such that thefoaming cells inside thereof are closed cells that do not communicatewith each other. Accordingly, the suppression effect on the waterabsorption rate is increased. For example, even if portions of thefoaming cells inside the foamed part of the run channel main body 50 areexposed to the surface, such as the cut end surfaces of the run channelmain body 50, water is satisfactorily prevented from being absorbedinside the foamed part of the run channel main body 50 from the exposedfoaming cells.

Hereinafter, a method for manufacturing the first to the fourth glassrun channels 31 to 34, which configures the front side glass run channelassembly 30 including the run channel main body 50, will be described.

First of all, a thermoplastic elastomer material and a masterbatchmaterial are prepared. The thermoplastic elastomer material is a maincomponent of the foamed part of the run channel main body 50. Themasterbatch material is made by mixing the thermal expansion capsuleswith a thermoplastic resin material that is the same kind of material asthe thermoplastic elastomer material or a material which is misciblewith the thermoplastic elastomer material.

As the thermoplastic elastomer material that is a main component of thefoamed part of the run channel main body 50, for example, a material ismade by mixing EPDM (ethylene propylene diene copolymer) and PP(polypropylene), and then mixing additives such as a plasticizer orcolorant thereto.

As the masterbatch material, a material is used in which the theretoexpandable capsules (trade name of ADVANCELL, manufactured by SEKISUICHEMICAL CO., LTD., average particle diameter: 22 μm to 32 μm, expansionstart temperature: 160 degrees Celsius to 180 degrees Celsius, all froma catalogue) and PE (polyethylene) are mixed in a ratio of 1:1 in theweight ratio and made into a pellet.

The thermoplastic elastomer material in which the thermal expansioncapsules are mixed is not limited to the above-described material. Forexample, although the above-described thermoplastic elastomer is acrosslinkable material, a noncrosslinkable thermoplastic elastomermaterial may be used.

It is preferred that the thermoplastic elastomer material has a JISAhardness of 70 to 90 degrees.

The pellets of the thermoplastic elastomer material and the pellets ofthe masterbatch material are put into a hopper of the extrusion moldingmachine. Here, the pellets of the thermoplastic elastomer material andthe pellets of the masterbatch material are put into the hopper afterbeing measured in weight and mixed in an adjusted weight ratio, whichare set in advance. After that, the mixed material is sequentiallytransferred within a cylinder from the hopper by a screw that is rotatedwithin the cylinder of the extrusion molding machine.

In the first exemplary embodiment, 1.0 to 4.0 parts by weight of themasterbatch material (0.5 to 2.0 parts by weight of the thermalexpansion microcapsules) are mixed to 100 parts by weight of thethermoplastic elastomer material.

It is preferred that 2.0 parts by weight of the masterbatch material(1.0 part by weight of the thermal expansion microcapsules) are mixed to100 parts by weight of the thermoplastic elastomer material.

The mixed material of thermoplastic elastomer material and themasterbatch material is heated and pressurized while being mixed in theextrusion molding machine so that it becomes a foamable polymer materialin a molten state. Thus, the foamable polymer material in the moltenstate is supplied to a first material flow passage that has a shapecorresponding to the run channel main body 50 within a mold which isconnected to the outlet of the cylinder of the extrusion moldingmachine.

Meanwhile, the low friction material for forming the low friction layers52 a, 53 a, 51 a, 63 and 66, the coefficient of kinetic friction ofwhich is smaller than that of the foamable polymer material, is put intoanother extrusion molding machine (cylinder) from a hopper that isdifferent from the above described hopper via a measurer and is suppliedto the second material flow passage that corresponds to the low frictionlayers 52 a, 53 a, 51 a, 63 and 66 within the mold while being heated,pressurized and melted.

The first and second material flow passages of the mold are joinedtogether in the mold. And the melted material of the first and secondmaterial flow passages is extruded at the same time from the extrusionoutlet which is formed at an end (downmost stream side) of the mold. Thetemperature near a material inlet of the extrusion molding machine isset to, for example, about 120 degrees Celsius to 150 degrees Celsius (atemperature at which the thermal expansion capsules do not break). Thetemperature is gradually increased from the material inlet toward themold, and the temperature near the extrusion outlet of the mold is setto about 210 degrees Celsius.

Just after the foamable polymer material and the thermoplastic elastomermaterial as the low friction material having a small coefficient ofkinetic friction are extruded from the extrusion outlet of the mold, thepressure that is applied to the materials is released so that thethermal expansion capsules (microcapsules) in the foamable polymermaterial are expanded and foamed. An intermediate molding body, whichhas the cross-sectional shape of the run channel main body 50 and theglass run channels (the first to the fourth glass run channels 31 to 34)having the low friction layers 52 a, 53 a, 51 a, 63 and 66, is formedthereby.

After the thermal expansion capsules (the microcapsules) are foamed, theintermediate molding body is cooled, solidified and cut in apredetermined length, thereby manufacturing the glass run channels (thefirst to the fourth glass run channels 31 to 34).

Accordingly, the first to the fourth glass run channels 31 to 34 thatare attachable to the front door 10 are easily manufactured by theabove-described manufacturing method.

After the first to the fourth glass run channels 31 to 34 are formed bythe extrusion molding, the end surfaces of the first to the fourth glassrun channels 31 to 34 that face each other are connected integrallythrough the first to the third connecting bodies 41, 42 and 43 that areformed by the injection molding, thereby manufacturing the front sideglass run channel assembly 30.

A rear side glass run channel assembly 130 that is attachable to a reardoor 110 can be also manufactured in the same manner as in the abovedescribed manufacturing method.

As shown in FIGS. 1 and 2, a part of the rear side glass run channelassembly 130 is formed in the elongated shape by the polymer material(the thermoplastic elastomer material) so as to be mounted on the windowframe 120 of the rear door 110 as the vehicle door and guide the movingup and down of the windowpane 115. The rear side glass run channelassembly 130 has the first to fifth glass run channels 131, 132, 133,134 and 135 that are formed in the elongated shape by the extrusionmolding, and the first to fourth connecting bodies 141, 142, 143 and 144that are formed by the injection molding.

The first glass run channel 131 is formed in the same structure as thatof the first glass run channel 31 of the front side glass run channelassembly 30 (see FIG. 3).

Further, the run channel main body that forms the main part of thesecond to fifth glass run channels 132 to 135 that constitute the rearside glass run channel assembly 130 is constituted in the same manner asthe run channel main body that constitutes the main part of the firstglass run channel 131 except that the cross-sectional shape thereof isdifferent.

Example 1

The water absorption rate and the specific gravity of the foamablepolymer that forms the foamed part of the run channel main bodyaccording to the first exemplary embodiment are measured.

As the thermoplastic elastomer material, an olefin-system thermoplasticelastomer having a ESA hardness of 80 degrees is used.

As the thermal expansion capsules (the microcapsules), “ADVANCELL”,manufactured by SEKISUI CHEMICAL CO., LTD., is used.

1 to 3 parts by weight of the thermal expansion capsules are mixed with100 parts by weight of the thermoplastic elastomer.

When the thermal expansion capsules are mixed, the masterbatch, in whichthe thermal expansion capsules are dispersed beforehand into the sameamount of polyethylene, is used.

Specific molding conditions of the extrusion molding are as follows.

Temperatures (the temperatures in four positions from the upstream sidetoward the downstream side) of each of the portions of the cylinder: 150degrees Celsius, 170 degrees Celsius, 175 degrees Celsius and 180degrees Celsius.

Temperature of the cylinder head: 200 degrees Celsius.

Temperature of the outlet: 200 degrees Celsius.

Rotation speed of the screw: 10 rpm, 30 rpm and 60 rpm.

The above described conditions are combined as shown in Table 1, andsamples No. 1 to No. 6 are formed. Sample No. 7 is a sample in which thethermal expansion capsules are not mixed.

The water absorption rate is obtained by measuring the water absorptionrate of a plurality (N=5 to 8) of measuring pieces and calculating theaverage value of the water absorption rates, according to the abovedescribed method.

The specific gravity is measured using an electronic densimeter MD-200Smanufactured by ALFA MIRAGE CO., LTD.

The relation of the water absorption rate and the specific gravity thatare measured by the above-described method are illustrated in theexplanation drawing (graph) of FIG. 5 and Table 1.

TABLE 1 Mixed amount of the capsules [parts Rotation Water Sample byweight] speed of Specific absorption Suitable No. Capsules screw gravityrate [%] or not 1 3 60 0.49 17.00 Not Suitable 2 2 60 0.53 1.40 Suitable3 1.5 60 0.60 0.40 Suitable 4 1 60 0.64 0.30 Suitable 5 1 30 0.66 0.18Suitable 6 1 10 0.70 0.12 Suitable 7 0 10 0.89 0.00 Not Suitable

Referring to FIG. 5 and Table 1, in a case where the mixed amount of thethermal expansion capsules is 3 parts by weight (sample No. 1), althoughthe specific gravity is less than 0.50, the water absorption rate isexceeds 15%, and the water absorption rate is not 5% or less.

Meanwhile, in a case where the mixed amount of the thermal expansioncapsules is 2 parts by weight or less (sample No. 2 to No. 6), thespecific gravity is 0.50 or more and the water absorption rate is 2% orless.

Further, in a case where the mixed amount of the thermal expansioncapsules is 1.5 or less parts by weight (samples No. 3 to No. 6), thespecific gravity is 0.60 or more and the water absorption rate is 1% orless.

In a case where the thermal expansion capsules are not mixed (sample No.7), since the foaming is not generated by the thermal expansioncapsules, the specific gravity is 0.89 and the weight reduction effectcan not be obtained.

In samples No. 4 to No. 6, the mixed amount of the thermal expansioncapsules is constant so that the specific gravity and the waterabsorption rate are adjusted by changing the rotation speed of thescrew.

If the rotation speed of the screw is increased, there is a tendencythat the degree of foaming increases, whereby the specific gravitydecreases and the water absorption rate increases.

Meanwhile, if the rotation speed is decreased, there is a tendency thatthe degree of foaming decreases, whereby the specific gravity increasesand the water absorption rate decreases.

While the first exemplary embodiment has been showed and described, theinvention is not limited to the first exemplary embodiment, and it willbe understood by those skilled in the art that various changes in formand details may be made therein without departing from the spirit andscope of the invention.

For example, as shown in FIG. 4, the window frame may be formed by awindow frame sash of a sash type. In this case, a window frame sash 220that constitutes the window frame is formed, which is separated from thedoor panel of the vehicle opening and closing doors (the front door, therear door or the like) and is fixed to the door panel. A run mountingrecess 225 is formed at the window frame sash 220. A glass run channel231 has the same configuration as the glass run channel of the firstexemplary embodiment except the glass run channel 231 has across-section that is mountable to the run mounting recess 225 and has ahigh friction layer 269 of which the coefficient of static friction islarger than the run channel main body 250. The glass run channel 231also achieves the same functional effect as the glass run channel of thefirst exemplary embodiment.

The present invention provides illustrative, non-limiting aspects asfollows:

(1) According to a first aspect, there is provided a glass run channelhaving an elongated shape, which is mounted on a run mounting portion ofa window frame of a vehicle door, guides moving up and down of awindowpane and is made of a polymer material, the glass run channelcomprising: a run channel main body that forms the main part of theglass run channel, the run channel main body including, a base bottomportion which is provided at a position facing an end surface of thewindowpane; an interior side wall portion which extends from a width endof the base bottom portion, an exterior side wall portion which extendsfrom another width end of the base bottom portion, an interior seal lip,which projects toward the base bottom portion from an opening side endof the interior side wall portion and elastically contacts a firstsurface of the windowpane, and an exterior seal lip, which projectstoward the base bottom portion from an opening side end of the exteriorside wall portion and elastically contacts a second surface of thewindowpane, wherein the run channel main body has a foamed part made ofa foamable polymer material that includes a thermoplastic elastomermaterial and thermal expansion capsules, and has foaming cells which areformed by expansion of the thermal expansion capsules, and wherein awater absorption rate of the foamed part of the run channel main body isadjusted to 5% or less.

According to this configuration, since the foamed part of the runchannel main body that forms the main part of the glass run channel ismade of the foamable polymer material that include the thermoplasticelastomer material and the thermal expansion capsules, the run channelmain body can be satisfactorily reduced in weight compared to the glassrun channel made of rubber. The water absorption rate of the foamed partof the run channel main body is adjusted to 5% or less so that water isnot easily absorbed within the foaming cells. As a result, in themanufacturing process of the glass run channel, since only a littleamount of water is absorbed within the glass run channel, the littleamount of water is not required to be vaporized and dried after theglass run channel is cooled and solidified by the cooling water so thatthe drying process time can be shortened or the drying process can becancelled. Further, the glass run channel can be suppressed fromabsorbing water even in a using state in which the glass run channel ismounted on the run mounting portion of the window frame of the frontdoor or the rear door. Thus, the defect that, when outdoor temperatureis a low temperature, water within the glass run channel is frozen, theglass run channel is excessively hardened and abnormal noise isgenerated when the windowpane is moved up and down, are prevented.

(2) According to a second aspect, there is provided the glass runchannel according to the first aspect, wherein the water absorption rateof the foamed part of the run channel main body is adjusted to 1% orless.

According to this configuration, since the water absorption rate of thefoamed part of the run channel main body is adjusted to 1% or less,water is even less easily absorbed within the foaming cells.

(3) According to a third aspect, there is provided the glass run channelaccording to the first or second aspect, wherein the specific gravity ofthe foamed part of the run channel main body is 0.50 to 0.75.

According to this configuration, since the specific gravity of thefoamed part of the run channel main body is adjusted to 0.50 to 0.75,the weight reduction effect is large. In other words, if the specificgravity of the foamed part of the run channel main body is smaller than0.50, there is a concern that the water absorption rate will increase.Further, if the specific gravity of the foamed part of the run channelmain body is larger than 0.75, the weight reduction effect decreases.

(4) According to a fourth aspect, there is provided the glass runchannel according to the first or second aspect, wherein the specificgravity of the foamed part of the run channel main body is 0.65.

According to this configuration, since the specific gravity of thefoamed part of the run channel main body is adjusted to 0.65, the weightreduction effect further increases.

(5) According to a fifth aspect, there is provided the glass run channelaccording to any one of the first to fourth aspect, wherein the foamablepolymer material, which forms the foamed part of the run channel mainbody, includes 100 parts by weight of the thermoplastic elastomermaterial and 0.5 to 2.0 parts by weight of the thermal expansioncapsules.

According to this configuration, the weight reduction is satisfactorilyperformed and the water absorption rate can be maintained at 5% or less.In other words, if the thermal expansion capsules are less than 0.5parts by weight, the weight reduction effect decreases. If the thermalexpansion capsules are more than 2.0 parts by weight, there are concernsthat the capsules will enter an excessively foamed state so thatrigidity, tensile strength and the like will decrease, or the foamingcells will be continuous to each other so that it is difficult tomaintain the water absorption rate to 5% or less.

(6) According to a sixth aspect, there is provided the glass run channelaccording to any one of the first to fourth aspect, wherein the foamablepolymer material, which forms the foamed part of the run channel mainbody, includes 100 parts by weight of the thermoplastic elastomermaterial and 1.0 parts by weight of the thermal expansion capsules.

According to this configuration, the weight reduction effect and thesuppression effect on the water absorption increases.

(7) According to a seventh aspect, there is provided the glass runchannel according to any one of the first to sixth aspect, wherein thefoamed part of the run channel main body is formed such that the foamingcells inside the foamed part of the run channel main body are closedcells that do not communicate with external air.

According to this configuration, fluid can be satisfactorily preventedfrom being absorbed in the foamed part of the run channel main body fromthe surface thereof, whereby the effect of the water absorption ratebeing suppressed can increase.

(8) According to an eighth aspect, there is provided the glass runchannel according to the seventh aspect, wherein the foamed part of therun channel main body is formed such that the foaming cells inside thefoamed part of the run channel main body are closed cells that do notcommunicate with each other.

According to this configuration, the effect of the water absorption ratebeing suppressed can increase, and further, fluid can be satisfactorilyprevented from being absorbed from the cut end surface of the runchannel main body.

(9) According to a ninth aspect, there is provided a glass run channelassembly including at least two glass run channels according to thefirst aspect, wherein the at least two glass run channels are joined andconstituted in an integrally continuous shape to each other by aconnecting body.

According to this configuration, at least two glass run channels arejoined in integrally continuous shape by connecting bodies so that theglass run channel assembly having a desired shape and length can beeasily obtained. The connecting body is injection-molded between endsurfaces of at least two glass run channels that face each other so thateach of the end surfaces can also be reliably connected.

(10) According to a tenth aspect, there is provided a method ofmanufacturing the glass run channel according to the first aspect, themethod comprising: inputting a thermoplastic elastomer material and amasterbatch material into a extrusion molding machine in an adjustedweight ratio, wherein the masterbatch material is made by mixing thethermal expansion capsules with the thermoplastic resin material, thethermoplastic resin material being the same material as thethermoplastic elastomer material or being miscible with thethermoplastic elastomer material, providing a foamable polymer materialby heating and pressurizing each material while mixing in the extrusionmolding machine; supplying the foamable polymer material to a mold:extruding the foamable polymer material from an outlet of the mold ofthe extrusion molding machine after supplying the foamable polymermaterial to the mold; forming a molding body of a shape corresponding toa cross-sectional shape of the glass run channel by expanding andfoaming the thermal expansion capsules immediately after the extrusion;and cooling and solidifying the molding body after the foaming.

According to this configuration, by using the masterbatch in which thethermal expansion capsules are mixed with the thermoplastic resinmaterial which is the same material as the thermoplastic elastomermaterial or is miscible with the thermoplastic elastomer material andperforming mixing in the extrusion molding machine so as to obtain thefoamable polymer material, the thermal expansion capsules are notlocally distributed and can be substantially evenly dispersed and mixedin the foamable polymer material. Accordingly, the glass run channelaccording to the first aspect can be easily manufactured.

(11) According to an eleventh aspect, there is provided a glass runchannel having an elongated shape, which is mounted on a run mountingportion of a window frame of a vehicle door, guides moving up and downof a windowpane and is made of a polymer material, the glass run channelcomprising: a run channel main body that forms the main part of theglass run channel, the run channel main body including, a base bottomportion which is provided at a position facing an end surface of thewindowpane; an interior side wall portion which extends from a width endof the base bottom portion, an exterior side wall portion which extendsfrom another width end of the base bottom portion, an interior seal lip,which projects toward the base bottom portion from an opening side endof the interior side wall portion and elastically contacts a firstsurface of the windowpane, and an exterior seal lip, which projectstoward the base bottom portion from an opening side end of the exteriorside wall portion and elastically contacts a second surface of thewindowpane, wherein the base bottom portion, the interior side wallportion, the exterior side wall portion and the interior seal lipportion are made of a foamable polymer material that includes athermoplastic elastomer material and thermal expansion capsules, and hasfoaming cells which are formed by expansion of the thermal expansioncapsules, and wherein each water absorption rate of the base bottomportion, the interior side wall portion, the exterior side wall portionand the interior seal lip portion is adjusted to 5% or less.

1. A glass run channel having an elongated shape, which is mounted on arun mounting portion of a window frame of a vehicle door, guides movingup and down of a windowpane and is made of a polymer material, the glassrun channel comprising: a run channel main body that forms the main partof the glass run channel, the run channel main body including, a basebottom portion which is provided at a position facing an end surface ofthe windowpane; an interior side wall portion which extends from a widthend of the base bottom portion, an exterior side wall portion whichextends from another width end of the base bottom portion, an interiorseal lip, which projects toward the base bottom portion from an openingside end of the interior side wall portion and elastically contacts afirst surface of the windowpane, and an exterior seal lip, whichprojects toward the base bottom portion from an opening side end of theexterior side wall portion and elastically contacts a second surface ofthe windowpane, wherein the run channel main body has a foamed part madeof a foamable polymer material that includes a thermoplastic elastomermaterial and thermal expansion capsules, and has foaming cells which areformed by expansion of the thermal expansion capsules, and wherein awater absorption rate of the foamed part of the run channel main body isadjusted to 5% or less.
 2. The glass run channel according to claim 1,wherein the water absorption rate of the foamed part of the run channelmain body is adjusted to 1% or less.
 3. The glass run channel accordingto claim 1, wherein the specific gravity of the foamed part of the runchannel main body is 0.50 to 0.75.
 4. The glass run channel according toclaim 1, wherein the specific gravity of the foamed part of the runchannel main body is 0.65.
 5. The glass run channel according to claim1, wherein the foamable polymer material, which forms the foamed part ofthe run channel main body, includes 100 parts by weight of thethermoplastic elastomer material and 0.5 to 2.0 parts by weight of thethermal expansion capsules.
 6. The glass run channel according to claim1, wherein the foamable polymer material, which forms the foamed part ofthe run channel main body, includes 100 parts by weight of thethermoplastic elastomer material and 1.0 parts by weight of the thermalexpansion capsules.
 7. The glass run channel according to claim 1,wherein the foamed part of the run channel main body is formed such thatthe foaming cells inside the foamed part of the run channel main bodyare closed cells that do not communicate with external air.
 8. The glassrun channel according to claim 7, wherein the foamed part of the runchannel main body is formed such that the foaming cells inside thefoamed part of the run channel main body are closed cells that do notcommunicate with each other.
 9. A glass run channel assembly includingat least two glass run channels according to claim 1, wherein the atleast two glass run channels are joined and constituted in an integrallycontinuous shape to each other by a connecting body.
 10. A method ofmanufacturing the glass run channel according to claim 1, the methodcomprising: inputting a thermoplastic elastomer material and amasterbatch material into a extrusion molding machine in an adjustedweight ratio, wherein the masterbatch material is made by mixing thethermal expansion capsules with the thermoplastic resin material, thethermoplastic resin material being the same material as thethermoplastic elastomer material or being miscible with thethermoplastic elastomer material, providing a foamable polymer materialby heating and pressurizing each material while mixing in the extrusionmolding machine; supplying the foamable polymer material to a moldextruding the foamable polymer material from an outlet of the mold ofthe extrusion molding machine after supplying the foamable polymermaterial to the mold; forming a molding body of a shape corresponding toa cross-sectional shape of the glass run channel by expanding andfoaming the thermal expansion capsules immediately after the extrusion;and cooling and solidifying the molding body after the foaming.
 11. Aglass run channel having an elongated shape, which is mounted on a runmounting portion of a window frame of a vehicle door, guides moving upand down of a windowpane and is made of a polymer material, the glassrun channel comprising: a run channel main body that forms the main partof the glass run channel, the run channel main body including, a basebottom portion which is provided at a position facing an end surface ofthe windowpane; an interior side wall portion which extends from a widthend of the base bottom portion, an exterior side wall portion whichextends from another width end of the base bottom portion, an interiorseal lip, which projects toward the base bottom portion from an openingside end of the interior side wall portion and elastically contacts afirst surface of the windowpane, and an exterior seal lip, whichprojects toward the base bottom portion from an opening side end of theexterior side wall portion and elastically contacts a second surface ofthe windowpane, wherein the base bottom portion, the interior side wallportion, the exterior side wall portion and the interior seal lipportion are made of a foamable polymer material that includes athermoplastic elastomer material and thermal expansion capsules, and hasfoaming cells which are formed by expansion of the thermal expansioncapsules, and wherein each water absorption rate of the base bottomportion, the interior side wall portion, the exterior side wall portionand the interior seal lip portion is adjusted to 5% or less.